Driving-rod connection for loom let-off mechanism



: March 11, 1930. T. a REID 1,750,606

DRIVING ROD CONNECTION FOR LQOI LET-OFF IECHANISI Filed Oct. 23,1928

Fig.1.

IIFIVUN'OI Thomas E. Reid b mwkwwear takes place between the casting andthe Fatented Mar. 11, 1930 UNITED STATES PATENT OFFICE THOMAS E. REID,OF CONCORD, NORTH CAROLINA, ASSIGNOR- TO DRAPER CORPORA- TION, OFHOPE-DALE, MASSACHUSETTS, A CORPORATION OF MAINE DRIVING-ROD CONNECTIONFOR LOOM LET-OFF MECHANISM Application filed October 23, 1928. SerialNo. 314,445.

This invention relates to a let-off mechanism for looms and particularlyto the actuating mechanism therefor.

A let-off mechanism has for its purpose the control of the rotation of awarp beam in the loom so as to let 01f under even tension the warps fromthe beam during and, as required by, the weaving operation. Thecontrolling mechanism is usually operated by connection 0 to the layrocker shaft so that during each cycle of movement of the lay apredetermined amount of warps is let 0H.

In a familiar type of let-off mechanism, a rocker arm is secured to thelay rock shaft and connected by a driving rod to a pallet or pawlcarrying lever which controls the opera tion of the let-off mechanism. Alost motion connection is necessary between the rocker arm and thedriving rod. The usual connection at this point consists of a stud caston the rocker arm and a longitudinally slotted casting on the drivingrod cooperating therewith. As these parts are seldom, if ever,lubricated and are not carefully finished, a great deal of studinterfering with the proper operation of the mechanism and necessitatingfrequent replacement of the main portion of the rocker arm, of a castingon the driving rod, or of both.

The object of the invention is primarily to provide a simple andefficient form of connection between the rocker arm and the driving rodwhich will operate for long periods of time without substantial wear,without necessity of replacement of parts and without requiringlubrication.

The nature and objects of the invention will appear more fully from theaccompanying description and drawings and will be particularly pointedout in the claims.

As the invention relates to but one feature of construction in thelet-off mechanism, and as the construction and operation of the letoffmechanism are well known and familiar to those skilled in the art, itwill be sufficient to illustrate only those parts of a familiar type ofmechanism with which the invention is particularly concerned in orderfully to disclose a simple and preferred embodiment of the invention.

In the drawings:

Fig. 1 is a side elevation of the lower rear portion of the side frameof a loom with only those parts shown with which the present inventionis concerned.

V Fig. 2 is a perspective view of a preferred form of stud.

Fig. 3 is an inside elevation on a larger scale of the upper end oftherocker arm.

Fig. 4 is a view in vertical cross section taken on the line 44 of Fig.3 on a still larger scale and with the stud shown in elevation.

In the construction illustrated, the loom side frame 1 supports one endof the usual lay rocker shaft 2 carrying the lay swords 3. The rockerarm is secured to this rock shaft 2 and is shown as made in two parts, 4and 5, adjustably connected together at 6 according to the usualpractice. This rocker arm which thus swings with the lay is connected bya driving rod 7 to a pallet lever 8 fulcrumed at 9 and carrying a pawl10 cooperating with a ratchet gear, a portion of which is shown at 11,and which controls the operation of the let-ofl mechanism. There must bea lost motion connection in this type of mechanism between the drivingrod and the rocker arm because the rocker arm always swings forward tothe same extent and always carries the pawl 10 rearward to the samepoint, while the forward movement of the pawl 10, or the movement towardthe front of the loom, varies.

In the construction illustrated,the driving rod 7v is provided at itsforward end with a longitudinally slotted casting 12 secured thereto asby the set screw 13. A headed steel stud is detachably secured in thefree or upper end of the rocker arm to cooperate with this slottedcasting and a preferred form of stud is shown in Figs. 2 and 4;. Thisstud comprises a large flat head 14:, a cylindrical shank 15, apolygonal end 16, herein shown as square, terminating in a screwthreadedsection 17. A nut 18 is provided to fit thethreadedi-section 17 and asuitable washer 19 is provided. The polygonal end 16 of the stud fits acorresponding polygonal aperture 20 formed in the upper end of therocker arm 4. The stud is inserted through the longitudinal slot 21 ofthe casting 12 and then detachably but rigidly secured in the rocker armby screwing the nut up with the shoulder 22 of the stud shank 15abutting the outer side of the rocker arm and with the washer 19abutting the inner side.

It will thus be seen that the casting 12 is guided between the rockerarm and the head of the stud and that its slot slides on the shank 15 ofthe stud. As the stud is made of steel and the casting 12 is usually ofiron, these parts operate together with very little wear, even when thecasting is not finished and even when no lubrication is provided.Furthermore, when any wear does take place, the stud may be rotarilyadjusted by giving it a quarter turn in the arm, thus bringing a freshsurface into sliding engagement with the casting.

While the end 16 is shown as square, this is but an example of anequilateral polygon which enables the stud to be rotarily adjusted inany one of a plurality of positions and it is not even necessary, in thebroader scope of the invention, that the stud have this polygonalsection but the stud is preferably rotarily adjustable in the arm.

There is thus provided a very simple and eflicient construction forobviating the defects heretofore existing in this mechanism and securinglong life to these parts.

Having thus described the invention, what is claimed as new, and desiredto be secured by Letters Patent, is:

1. In a let-off mechanism for looms, a rocker arm having a polygonalaperture in its free end, a pallet lever, a driving rod pivoted at oneend to the pallet lever and having a longitudinally slotted casting atthe other end, a steel stud having a head, a cylindrical shank and apolygonal end fitting the aperture in the arm, and means for detachablysecuring the stud in the end of the rocker arm with the casting guidedbetween the arm and the head of the stud and with the slot riding in theshank of the stud.

2. In a let-off mechanism for looms, a rocker arm having a polygonalaperture in its free end, a pallet lever, a driving rod pivoted at oneend to the pallet lever and having a longitudinally slotted casting atthe other end, a steel stud having a head, a cylindrical shank, apolygonal end fitting the aperture in the arm and terminating in areduced threaded section, and a nut fitting said threaded section andacting detachably to secure the stud in the end of the rocker arm withthe casting guided between the arm and the head of the stud and with theslot riding upon the shank of the stud.

3. In a let-off mechanism, the construction defined in claim 1, in whichthe polygonal aperture in the rocker arm and the polygonal end of thestud are equilateral to enable the stud to be rotarily adjusted in thearm.

In testimony whereof, I have signed my name to this specification.

THOMAS E. REID.

